Airtel today introduced a new add on plan for existing BlackBerry postpaid customers. For a monthly rent of Rs. 299, which is in addition to the regular BlackBerry plan, a user will be able to enjoy 3G service. So in short, if you’re paying Rs. 399, Rs. 599 or Rs. 898 for the BlackBerry plan, you can add this plan to get unlimited usage on the BlackBerry phone at 3G speeds whereas 1GB of free data if you use BlackBerry as a modem.